Assuming you are using Windows XP or Vista, you can use the DISKPART utility to delete these OEM partitions from DELL and other hard drives.

If you have data anywhere on the drive that you will be deleting the EISA partition from, backup that data now.

Connect the drive to the computer. If it is an IDE drive then do this with a USB-to-IDE device, or connect the drive directly to the IDE cable. If ti is a SATA drive then do this with a USB-to-SATA device, or connect the drive direclty to the SATA controller on the motherboard. In essence, the drive must be connected to the PC and it must be “seen” by the operating system.

In the command prompt type DISKPART <ENTER>. This starts up the DISKPART utility.

Type LIST DISK <ENTER>. This shows the all the disks connected to the computer. Decide which one is the one you are wanting to delete the EISA / OEM partition from, and make note of which number it is.

Type SELECT DISK n<ENTER> (where n = the number of the disk you noted in step 4)

Type LIST PART <ENTER>. This shows the all the partitions contained in the drive you are working with. Decide which one is the one you are wanting to delete, and make note of which number it is.

Type SELECT PART n<ENTER>(where n = the number of the partition you noted in step 6)

Type DELETE PART OVERRIDE <ENTER>. This deletes the partition you selected.

You are done with deleting the partition. If you want to, you may now EXTEND another adjacent partition into that free space you just created.